1. Field of the Invention
The invention herein pertains to containers for delivery of prepared food and particularly of foods which are desirably warmed and maintained at adequate temperatures during delivery.
2. Description of the Prior Art and Objectives of the Invention
In recent years it has become increasingly popular to deliver prepared foods such as vegetable plates, sandwiches, French fries, pizzas and the like. Companies which provide home food delivery services are constantly seeking ways to improve the service, food quality and taste due to the competitive nature of the business. Insulated food and pizza delivery bags have been used for many years whereby warmed foods will retain a certain temperature level during delivery, depending on the transportation time and delivery route length.
One prior food delivery device is seen in U.S. Pat. No. 4,182,405 which provides a food temperature maintenance device for use in hospitals, hotels and otherwise. U.S. Pat. No. 4,806,736 demonstrates a portable pizza delivery bag which includes a heating unit having an electrical heating strip. U.S. Pat. No. 4,983,798 teaches a food-warming device such as for warming coffee. U.S. Pat. No. 5,052,369 includes a food heat storage system which uses a micro-crystalline phase change wax as may be heated by a microwave oven for heat retention of food. While all the devices listed in the prior patents are advantageous under certain circumstances, the need for a simple, inexpensive delivery bag and a safe, efficient element has remained. Thus, it is one objective of the present invention to provide a food delivery container and removable heating element which will allow food to be kept in a warmed condition for several hours.
It is another objection of the present invention to provide a method for heating food using a heating element which can be warmed in a standard convection oven in one embodiment, and in another embodiment, includes an integral electric grid for heating purposes
It is a further objective of the present invention to provide a method of forming a heating element in which a phase change material is enwrapped in a permeable metal or polymeric envelope.
It is still another objective of the present invention to provide a heating element in which a polymeric ultra-high molecular weight polyethylene is utilized.
It is still a further objective of the present invention to provide a food delivery container in which the phase change material consists solely of a homogeneous ultra-high molecular weight polyethylene.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.